1. Field of the Invention
The present invention relates to a motor starting device to remotely control the starting of a motor incorporated in a toy by using an ultrasonic wave signal.
2. Description of the Prior Art
A prior art toy motor starting device is described, for example, in Japanese Utility Model Laid-Open Publication No. 60-49898 (1985).
In this prior art device, an external, audible, relatively loud sound is sensed by a sound-sensitive switch built in the toy, and the sensed signal is amplified to operate a motor driving circuit thereby to drive the toy motor for a pre-determined period of time.
However, in the prior art toy motor starting device, the toy motor is started by sensing an audible sound generated externally. If the sensitivity of the sound sensor is set at a high threshold to prevent faulty operation caused by extraneous noise, the toy motor can only be started by generating a loud sound, which may be annoying. On the other hand, in order to start the toy motor with a relatively soft sound, it is necessary to lower the threshold sensitivity of the sound sensor. In this case, the toy motor will be started by many extraneous sounds other than a generated sound intended by the user, and thus, it is impossible to srart the toy motor exactly as the user intends. Moreover, since the starting device is designed to sense external sound, it is difficult to srart the toy motor any appreciable distance away from the toy. Thus, the prior art toy motor starting device is unsatisfactory in some respects.